1. Field of the Invention
The present invention relates to a rivet gun, and more particularly to a rivet gun that has a detachable pneumatic cylinder assembly so that components inside the pneumatic cylinder assembly may be replaced easily without changing the whole pneumatic cylinder assembly. The maintenance costs of the rivet gun are reduced.
2. Description of Related Art
Taiwan utility model patents No. M286081 and M272598 disclose conventional rivet guns for mounting rivets on at least two pieces so that the rivets securely hold the pieces together. A rivet has a cap and a core pin. The cap is T-shaped and has an enlarged end and a mounting end. The core pin is mounted longitudinally through, protrudes out of the cap and has two ends and a ball formed on one end and adjacent to the mounting end of the cap.
A conventional rivet gun comprises a barrel, a handle, a trigger, a pin collector and a pneumatic cylinder.
The barrel has a front end, a rear end and a vise assembly that may vise and pull a core pin of a rivet on the front end into the barrel. The handle is mounted perpendicularly on the barrel and has air passageways. The collector is a jar mounted on the rear end of the barrel to collect the ejected core pins. The pneumatic cylinder is mounted movably under the handle and capable of activating the vise assembly through pneumatic and hydraulic means. Furthermore, the pneumatic cylinder may be connected to a high-pressure air source such as an air bottle to implement the ejection of the core pin.
When the rivet gun is used to rivet two pieces such as boards or plates together, a rivet is mounted through the pieces. The enlarged end of the cap of the rivet abuts an inside piece and the front end of the barrel of the rivet gun abuts the enlarged end. The trigger is pulled to activate the vise assembly to pull a core pin on the cap into the barrel. The ball on the core pin longitudinally compresses and radially expands the mounting end of the cap into T-shape so that the expanded mounting end hooks on an outside piece to complete the riveting process. Then, the air output by the high-pressure air source flows through the barrel from the front end to the rear end and sucks the broken core pin vised by the vise assembly backward into the collector
A casing of the pneumatic cylinder is formed integrally and manufactured by insert-molding processes to ensure good airtight/watertight properties thereof. However, disassembling the integrally formed casing is not easy, which raises the difficulty of repairing or replacing components inside the pneumatic cylinder. Therefore, the whole pneumatic cylinder is frequently replaced even though only few inside components are damaged. Maintaining the rivet gun is expensive.
To overcome the shortcomings, the present invention provides a rivet gun with detachable pneumatic cylinder assembly to mitigate or obviate the aforementioned problems.